<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CANVAS</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        #canvas {
            background: #000;
        }
    </style>
</head>
<body>
    <canvas id='canvas'></canvas>
    <script>
        const canvas = document.getElementById('canvas');
        canvas.width = 500;
        canvas.height = 500;
        var context = canvas.getContext("2d");
        context.beginPath();
        context.arc(100, 100, 50, 0, Math.PI * 2, true);
        context.closePath();
        context.fillStyle = 'rgb(255,255,255)';
        context.fill();
    </script>
</body>
</html>